1. Field of the Invention
The present invention relates to electronic paper, and, more particularly, to an apparatus for writing an image on the electronic paper.
2. Description of the Related Art
Various types of electronic paper have been introduced, among which electrophoretic electronic paper developed by E Ink Corporation has been widely used. Conventional methods for forming image patterns on electronic paper include a segment type method and a TFT (Thin Film Transistor) driving type method.
According to the segment type method, electronic paper has a backplane, which is provided with an image pattern to be displayed by the electronic paper. This type of method has an advantage in that it is easy to implement due to the simple driving circuit. However, the method has a disadvantage in that the backplane must have a micro electrode pattern to realize a detailed image, and that an increased number of segments to be driven makes control difficult. The TFT driving type method is used to solve these problems. The TFT driving type method has widely been used to drive an LCD (Liquid Crystal Display) or an OLED (Organic Light Emitting Diode), and is also used to drive electronic paper.
Conventional electronic paper requires a backplane to form an image pattern, and the price of TFT backplanes with high resolution has increased substantially. This has severely limited commercialization of large-size electronic paper. In addition, although electronic paper has the advantage of flexibility, backplanes required by the segment type and TFT driving type methods increase the thickness of the electronic paper and adversely affect the flexibility. Furthermore, it is very inefficient to apply electronic paper having the above-mentioned backplanes to application devices, which change the image pattern implemented on the electronic paper at a long cycle.
Therefore, there is a need for an apparatus for writing an image on electronic paper, which is adapted for application devices having a long image pattern change cycle.